I've read that engineers made planes that could break the sound barrier long before the sound barrier was broken. Why wasn't it broken? Because as the pilots neared the speed of sound, the plane would shake so violently that they'd be terrified that the aircraft would crack apart. Therefore, they always backed off the throttle.

Test pilot Chuck Yeager was the first to say, "Maybe it will be calmer on the other side." And he pressed through.

We expect change to be easy. Israel, thought for example, that freedom sounded great. But they weren't prepared for the violent shaking that would occur before the break-through. Many times they simply wanted to go back to the way things used to be.